Instancing code doesn't work

Hey guys,

For the last couple of days I got interested in Instanced Rendering. After some research and examples, I tried to do a little test myself.
I followed this guide: http://programming4.us/multimedia/8306.aspx , but I'm using LWJGL, so I ported it to Java:

And I have still open questions: Are there any linking errors (shader linker, not c++ linker)? You asked to to query those, that's why i provided the link with code. Second question is how your code looks like now (as you have added a fragment shader and other fixes).